The Plio-Pleistocene thrust belt-foredeep system in the Southern Apennines and Sicily (Italy)

The upper Pliocene-lower Pleistocene terrigenous deposits of the Southern Apennines and Sicily have significantly contributed to the understanding of the primary relationships between tectonics and sedimentation in an active thrust beltforedeep system. An integrated stratigraphic and structural investigation allowed the identification of thrust-related depositional sequences with systems tracts defined by specific stratigraphic signatures recording the complex migration path of the active thrusts in the mountain chain. In the foredeep basin, where thrust-related depositional sequences are better preserved, five basic depositional units have been distinguished: 1. Condensed section, underlying at the scale of the entire basin the major truncation surface at the base of the sequence. The deposition of this unit, indicative of a strongly reduced sediment supply, corresponds to a moment of forward transport of the allochthonous sheets over a long thrust flat (active-thrust-flat systems tract); 2. Syn-ramp wedge, made up of a prograding slope-fan system constituted of a thick body of gravity-driven deposits truncated upsection by the active frontal ramp of the allochthonous sheets (active-frontal-ramp systems tract). 3. Onlap-slope system, represented by retrograding basinal deposits onlapping the edge of the allochthonous sheets and featuring a backstepping passive margin (early stage of the backward-thrust-migration systems tract). 4. Transgressive system, made up of basinal deposits matching the maximum marine flooding of the tectonic wedge (late stage of the backward-thrust-migration systems tract); 5. Prograding shelf-margin system laterally grading into a prograding system of basin-floor turbidites (forward-thrustmigration systems tract). In the foreland areas, these depositional units grade into more or less condensed pelagic deposits, with the exception of unit 5 that may laterally pass towards the foreland into a shallower, flexure-related transgressive system. On top of the allochthonous sheets, both the active-thrustflat systems tract and the active-frontal-ramp systems tract are represented by shallowing-upward shelfal deposits (nappe sheet drape). In an early stage of the backward-thrust-migration systems tract, a retrograding fandelta/shelf system represents in the mountain chain the counterpart of the onlap-slope system. In a late stage, the retrograding fandelta/shelf system is overlain by a muddier transgressive system recording the progressive flooding of the tectonic wedge. The forward-thrust-migration systems tract is commonly represented by a prograding shoalwater delta/shelf system. Two different depositional settings, depending on the trajectories of the active thrusts in the mountain chain, have been recognized: mobile piggyback basin, developed in the hangingwall of an active thrust and flanked toward the foreland by an active ridge; wide passive shelf developed in thefootwall of an active thrust, open toward the foredeep basin

Upper Triassic basinal carbonates between the Molise and Sannio Nappes near Frosolone (Duronia, Molise): geological implications.

E’ stata riconosciuta nell’area di Duronia (Molise) l’esistenza di dolomie e calcari dolomitici con selce del Trias superiore riferibili alla Formazione dei “Calcari con Selce” delle Unità Lagonegresi. Questi carbonati bacinali, presenti nella parte basale della Falda Sannitica in prossimità del contatto con le Falde Molisane (Unità di Frosolone), sono stati interpretati in passato come olistoliti all’interno delle Argille Varicolori, come depositi della successione sannitica o come depositi della successione sicilide e ad essi sono state attribuite età che vanno dal Cretaceo superiore al Miocene medio. L’esistenza di depositi bacinali triassici nella regione molisano-sannitica ha come implicazione paleogeografica la continuazione verso nord di un ramo del Bacino Lagonegrese e come implicazione tettonica un forte raccorciamento tra i massicci carbonatici riferibili alla Piattaforma Appenninica e quelli riferibili alla Piattaforma Simbruini-Matese

A Geological Itinerary Through the Southern Apennine Thrust-Belt (Basilicata—Southern Italy)

Open access via Springer Compact AgreementPeer reviewedPublisher PD

Upward migration of Vesuvius magma chamber over the past 20 thousand years

International audienceForecasting future eruptions of Vesuvius is an important challenge for volcanologists, as its reawakening could threaten the lives of 700,000 people living near the volcano1,2. Critical to the evaluation of hazards associated with the next eruption is the estimation of the depth of the magma reservoir, one of the main parameters controlling magma properties and eruptive style. Petrological studies have indicated that during past activity, magma chambers were at depths between 3 and 16km (refs 3– 7). Geophysical surveys have imaged some levels of seismic attenuation, the shallowest of which lies at 8–9km depth8, and these have been tentatively interpreted as levels of preferential magma accumulation. By using experimental phase equilibria, carried out on material from four main explosive events at Vesuvius, we show here that the reservoirs that fed the eruptive activity migrated from 7–8km to 3–4km depth between the AD 79 (Pompeii) and AD 472 (Pollena) events. If data from the Pomici di Base event 18.5 kyr ago9 and the 1944 Vesuvius eruption7 are included, the total upward migration of the reservoir amounts to 9–11 km. The change of preferential magma ponding levels in the upper crust can be attributed to differences in the volatile content and buoyancy of ascending magmas, as well as to changes in local stress field following either caldera formation10 or volcano spreading11. Reservoir migration, and the possible influence on feeding rates12, should be integrated into the parameters used for defining expected eruptive scenarios at Vesuvius

Rapid ascent of rhyolitic magma at Chaitén volcano, Chile

International audienceAlthough rhyolite magma has fuelled some of the Earth's largest explosive volcanic eruptions, our understanding of these events is incomplete due to the previous lack of direct observation of these eruptions. On 1 May 2008, Chaitén volcano in Chile erupted rhyolite magma unexpectedly and explosively. Here, petrological and experimental data are presented that indicate that the hydrous rhyolite magma at Chaitén ascended very rapidly from storage depth to near-surface, with velocities of the order of one metre per second

Personalizing Cancer Pain Therapy: Insights from the Rational Use of Analgesics (RUA) Group

Introduction: A previous Delphi survey from the Rational Use of Analgesics (RUA) project involving Italian palliative care specialists revealed some discrepancies between current guidelines and clinical practice with a lack of consensus on items regarding the use of strong opioids in treating cancer pain. Those results represented the basis for a new Delphi study addressing a better approach to pain treatment in patients with cancer. Methods: The study consisted of a two-round multidisciplinary Delphi study. Specialists rated their agreement with a set of 17 statements using a 5-point Likert scale (0 = totally disagree and 4 = totally agree). Consensus on a statement was achieved if the median consensus score (MCS) (expressed as value at which at least 50% of participants agreed) was at least 4 and the interquartile range (IQR) was 3–4. Results: This survey included input from 186 palliative care specialists representing all Italian territory. Consensus was reached on seven statements. More than 70% of participants agreed with the use of low dose of strong opioids in moderate pain treatment and valued transdermal route as an effective option when the oral route is not available. There was strong consensus on the importance of knowing opioid pharmacokinetics for therapy personalization and on identifying immediate-release opioids as key for tailoring therapy to patients’ needs. Limited agreement was reached on items regarding breakthrough pain and the management of opioid-induced bowel dysfunction. Conclusion: These findings may assist clinicians in applying clinical evidence to routine care settings and call for a reappraisal of current pain treatment recommendations with the final aim of optimizing the clinical use of strong opioids in patients with cancer

Transitions between explosive and effusive phases during the cataclysmic 2010 eruption of Merapi volcano, Java, Indonesia

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions and may be linked to factors such as magma influx, ascent rate and degassing. However, the interplay between these factors is complex and the resulting eruptive behaviour often unpredictable. This paper focuses on the driving forces behind the explosive and effusive activity during the well-documented 2010 eruption of Merapi, the volcano’s largest eruption since 1872. Time-controlled samples were collected from the 2010 deposits, linked to eruption stage and style of activity. These include scoria and pumice from the initial explosions, dense and scoriaceous dome samples formed via effusive activity, as well as scoria and pumice samples deposited during subplinian column collapse. Quantitative textural analysis of groundmass feldspar microlites, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size distribution analysis, reveal that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. High-An (up to ∼80 mol% An) microlites from early erupted samples reveal that the eruption was likely preceded by an influx of hotter or more mafic magma. Transitions between explosive and effusive activity in 2010 were driven primarily by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in cycles of effusive and explosive activity. Explosivity during the 2010 eruption was enhanced by the presence of a ‘plug’ of cooled magma within the shallow magma plumbing system, which acted to hinder degassing, leading to overpressure prior to initial explosive activity

Pre- and syn-eruptive degassing and crystallisation processes of the 2010 and 2006 eruptions of Merapi volcano, Indonesia

The 2010 eruption of Merapi (VEI 4) was the volcano’s largest since 1872. In contrast to the prolonged and effusive dome-forming eruptions typical of Merapi’s recent activity, the 2010 eruption began explosively, before a new dome was rapidly emplaced. This new dome was subsequently destroyed by explosions, generating pyroclastic density currents (PDCs), predominantly consisting of dark coloured, dense blocks of basaltic andesite dome lava. A shift towards open-vent conditions in the later stages of the eruption culminated in multiple explosions and the generation of PDCs with conspicuous grey scoria and white pumice clasts resulting from sub-plinian convective column collapse. This paper presents geochemical data for melt inclusions and their clinopyroxene hosts extracted from dense dome lava, grey scoria and white pumice generated during the peak of the 2010 eruption. These are compared with clinopyroxene-hosted melt inclusions from scoriaceous dome fragments from the prolonged dome-forming 2006 eruption, to elucidate any relationship between pre-eruptive degassing and crystallisation processes and eruptive style. Secondary ion mass spectrometry analysis of volatiles (H2O, CO2) and light lithophile elements (Li, B, Be) is augmented by electron microprobe analysis of major elements and volatiles (Cl, S, F) in melt inclusions and groundmass glass. Geobarometric analysis shows that the clinopyroxene phenocrysts crystallised at depths of up to 20 km, with the greatest calculated depths associated with phenocrysts from the white pumice. Based on their volatile contents, melt inclusions have re-equilibrated during shallower storage and/or ascent, at depths of ~0.6–9.7 km, where the Merapi magma system is interpreted to be highly interconnected and not formed of discrete magma reservoirs. Melt inclusions enriched in Li show uniform “buffered” Cl concentrations, indicating the presence of an exsolved brine phase. Boron-enriched inclusions also support the presence of a brine phase, which helped to stabilise B in the melt. Calculations based on S concentrations in melt inclusions and groundmass glass require a degassing melt volume of 0.36 km3 in order to produce the mass of SO2 emitted during the 2010 eruption. This volume is approximately an order of magnitude higher than the erupted magma (DRE) volume. The transition between the contrasting eruptive styles in 2010 and 2006 is linked to changes in magmatic flux and changes in degassing style, with the explosive activity in 2010 driven by an influx of deep magma, which overwhelmed the shallower magma system and ascended rapidly, accompanied by closed-system degassing